I am trying to purchase replacement REAR shocks for my 1970 Camaro. The current shocks (see attached pictures) have an approx 2 in extension. I am not sure if this extension is normal or something the prior owner did. Without the extension the shock is too short. I am trying to select rear shocks replacements that do not require this extension. Any advice on why this extension is required? Any idea if a longer shock, like a 22.5 in, is the best solution? Thanks.